TOOLING DESIGN IMPROVEMENT OF MULTISTAGE COLD FORGING OF SPECIALTY SHAPED NUTS USING CAE AND 3D PRINTING

Abstract

Given its critical role in the fastener industry, cold forging is widely performed in automotive production, manufacturing, aviation, and 3C products. Personnel experience and trying error approaches provide a subjective and unreliable background despite their extensive use in fastener forming and die design owing to the difficulty in controlling the development schedule. This study used DEFORM-3D analysis software to investigate the die service life from producing specialty shaped nuts in a multistage cold forging process. Effective stress, effective strain, velocity field, and other quantitative metrics of dies and work-pieces can be obtained from numerical simulations. Herein, 3D printing technology is also implemented to create cold forging dies and deformed work-pieces for assessing the dimension of tooling assembly. This process allows engineers to gain a better understanding of the tooling design at development phase and derives the parts, which were previously just simulation results from DEFORM-3D forming software. Results can help a multistage processing factory establish a cold forming capacity for the development of new products. Consequently, the ability of self-design and self-manufacture of specialty shaped fasteners in Taiwan could be increased widely to enhance the international competitiveness of domestic industries.